Help with heater/ac - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Fruitloops · 01-06-2004, 11:42 AM

I need help trying to make my Jimmy blow hot air only. I have an ac but it is disconnected. When I turn on the switch to the blower it blows hot air out of the defrosters and floor vents, but still blows cold air outside air out the ac vents. The switch was an addition that was there when I purchased the Jimmy. It's my daily driver for the time being, and it has gotten very cold down here in TX. Any advice would be greatly appreciated.

red71cheyenne · 01-06-2004, 12:06 PM

Sounds like your partition in the heater box is not closing off the a/c part. May have to disassemble it and see if the cables are closing the passages off. You should only get defrost when its on defrost and heater will blow out the bottom and a/c vents when its on heater. Might also check the vacuum line to the damper on the passenger side vent in the cab. Good luck, Jeff.

JimKshortstep4x4 · 01-06-2004, 02:20 PM

This is a rather common problem with the AC diverter boxes. More than likely the door that diverts the air flow is broken at the hinge shaft so that the shaft moves but the door does not. The diverter box is easy to change out and my suggestion would be to buy a new one and change it out after you verify that it is bad.

Jim

Blue Beard · 01-06-2004, 03:40 PM

Have to agree on the diverter box.

Mine did the same thing.

Try the following two links, they only list back to 1980. But give them a call, I purchased one through one of these two. Just can't remember which one.

http://www.gmpartsdirect.com

http://www.partszoneonline.com

Fruitloops · 01-07-2004, 02:04 PM

Thank you for the help. Now I know where to look.

01-06-2004, 11:42 AM	#1
Fruitloops Registered User Join Date: May 2003 Location: Texas Posts: 34	Help with heater/ac I need help trying to make my Jimmy blow hot air only. I have an ac but it is disconnected. When I turn on the switch to the blower it blows hot air out of the defrosters and floor vents, but still blows cold air outside air out the ac vents. The switch was an addition that was there when I purchased the Jimmy. It's my daily driver for the time being, and it has gotten very cold down here in TX. Any advice would be greatly appreciated. __________________ '72 GMC 2 wd Jimmy '02 Toyota 4Runner (daily driver) '84 Chevy Silvarado short-bed (my boy's future truck) '71 VW bus buried in the back yard for my boys clubhouse!

01-06-2004, 12:06 PM	#2
red71cheyenne Back in the sticks Join Date: Jan 2001 Location: Fordland, MO Posts: 3,188	Sounds like your partition in the heater box is not closing off the a/c part. May have to disassemble it and see if the cables are closing the passages off. You should only get defrost when its on defrost and heater will blow out the bottom and a/c vents when its on heater. Might also check the vacuum line to the damper on the passenger side vent in the cab. Good luck, Jeff. __________________ 1971 Cheyenne C-10 w/700R4 and Tuned Port Injection 1969 K5 Blazer w/Tuned Port 2010 2SS/RS Flaming Orange Camaro 2011 K1500 Suburban 2014 K1500 Pickup 2008 Nissan Altima? The wifes' hoopty

01-06-2004, 03:40 PM	#4
Blue Beard Registered User Join Date: Jan 2003 Location: Washington State Posts: 8,834	Have to agree on the diverter box. Mine did the same thing. Try the following two links, they only list back to 1980. But give them a call, I purchased one through one of these two. Just can't remember which one. http://www.gmpartsdirect.com http://www.partszoneonline.com __________________ 1970 Chev CST 2003 Harley Fatboy 1975 Chevrolet Step Van 1956 Chev Bel Air 1977 Blazer 2WD For Sale $3000.00 1978 Blazer 2WD For Sale $7000.00 1978 Silverado 2005 Monte Carlo

01-07-2004, 02:04 PM	#5
Fruitloops Registered User Join Date: May 2003 Location: Texas Posts: 34	Thank you for the help. Now I know where to look. __________________ '72 GMC 2 wd Jimmy '02 Toyota 4Runner (daily driver) '84 Chevy Silvarado short-bed (my boy's future truck) '71 VW bus buried in the back yard for my boys clubhouse!

01-06-2004, 02:20 PM	#3
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	This is a rather common problem with the AC diverter boxes. More than likely the door that diverts the air flow is broken at the hinge shaft so that the shaft moves but the door does not. The diverter box is easy to change out and my suggestion would be to buy a new one and change it out after you verify that it is bad. Jim



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